Busardo Tisa

Identificación

This slim and small hawk is easily identified by its white iris and the white throat and dark mesial stripe. A white spot is sometimes visible on the back of the head. When perched, the wing tip nearly reaches the tip of the tail. The ceres are distinctly yellow and the head is dark with the underside of the body darkly barred. In flight, the narrow wings appear rounded with black tips to the feathers and the wing lining appears dark. The upper wing in flight shows a pale bar over the brown. The rufous tail is barred with a darker subterminal band. Young birds have the iris brownish and the forehead is whitish and a broad supercilium may be present. The only confusion can occur in places where it overlaps with the grey-faced buzzard (Butastur indicus), adults of which have a distinctive white supercilium. Fledgelings are reddish brown, unlike most other downy raptor chicks, which tend to be white.

Taxonomía

The specific name teesa is derived from the name in Hindi. The species was described on the basis of specimens collected by James Franklin who placed it in the genus Circus along with the harriers. The name Butastur was used to indicate that it appeared to be intermediate in characters to the Buteo buzzards and Astur, an old name for the sparrowhawks. Molecular phylogeny studies suggest that the genus is a sister group of Buteo and its relatives within the subfamily Buteoninae.

Nombre científico

Butastur teesa

Autoridad

(Franklin, 1831)

Orden

Accipitriformes

Familia

Accipitridae

Género

Butastur

Distribución y hábitat

This species is widely distributed in South Asia, throughout India in the plains and extending up to 1000 m in the Himalayas. It is a resident in Iran, Pakistan, Nepal, Bangladesh, and Myanmar. A form that is possibly of this species has been recorded in the Greater Sundas, Indonesia but this population is widely disjunct and has whiter and unmarked feathers on the thigh or "trousers" and vent, possibly representing a new form. It is absent from Sri Lanka and is probably absent from the Andamans. It is a summer visitor in northeastern Afghanistan. It is mainly found in the plains, but may go up to 1200 m altitude in the foothills of the Himalayas.<p>The usual habitat is in dry, open forest or cultivation. They are numerous in some areas, but declining. A survey in the late 1950s estimated about 5000 birds in the vicinity of Delhi in an area of about 50,000 km2 giving a density of 0.1 per square kilometre.

Migración

Especie residente

Comportamiento

Patrón migratorio: Especie residente.

Conservación

Tendencia poblacional: estable.

Tendencia poblacional

estable